Carrier dispatch system



Sem.. 17, 1935. F w MaCMARTlN 2,UM,7

` CARRIER DISPATCH SYSTEM Filed Jan. 21, 1950 5 Sheets-Sheet l 1W W3 F. w. MacMAm-IN M45? CARRIER DISPATCH SYSTEM 5 Sheets-Sheet 2 Filed Jan. 2l, 1950 Sept M, w35# F. w. MaoMARTlN OM-,57

CARRIER DI SPATCH SYSTEM Sp., H7, M65; l F. W, MaCMARTlN 2,034,578

CARRIER DISPATCH SYSTEM Sph l?, QY F. W, MaCMARTlN CARRIER DISPATCH SYSTEM Filed Jan. 21, 195o 5 sheet-sheet 5 ifi? 1,2%'

1,93 '1&2 12g Patented Sept. 17, 1935 UNITED ,STATES PATENT OFFICE CARRIER DISPATCH sYsrEM Application January N21, 1930, ASerial No. 422,313 I Y23 Claims.

This invention pertains to carrier dispatch systems such as are Vemployed in banks, large business cruces, Aindustrial establishments, and the like, for, transmitting documents, publica:

oftions, messages, rsmall articles 4of merchandise, etc., from one department, cir, or ,Operator to another, and finds its greatest utility in vsystems of highly complex character involving a great number` of stations such, for instance, as are 10.-? found in the home oces of the large insurance companies, such systems `being characterized by the capability of transmitting carriers from .any one of a large number .of stations .to any other station.

In accordance with the presentinvention and in `order to .avoid undue complexity Vof mechanical parts, I provide ,a .transfer or relay station as an essential partV of the system, such .station being so connected .to each Iof the sending .stations that 131)y all carriers pass through it .on their way from `one station to another, land .being so ,designed as to permit the number 4o f .operators at such relay or transfer station to be varied in accordance with changes in the volume of business Withoutsub- 25 1stantia1 sacrilcein efficiency. In such a system as above described, as vdistinguished from the ordinary store service system, carriers do not necessarily return to the station from which they are kfirst sent, and in accordance with the .30 3 present invention provision is vmade-forreplenishr me the supply at any kgiven statianfwhen auch Supply has .been redirige@ 9 1' @Xml-1ste@- While I have yherein chosen to illustrate the invention as embodied in a pneumatic tube ldis- 35rpatch system, I vvish it to Ebe understood that the i broader features of the invention may :iikevrise be embodiedrin dispatch systems vof `otljier types, and further, While I have herein illustrated one Sp arrangement `0f transferer relay ste-ties 49:1 which has been found convenient, efficient and saving of space, I Wish it to be understood that the invention may embody other forms of transfer station `and other specific larrangements of parts and means for moving Vcarriers thanthose 45 j herein shown and described.

In the accompanying drawings, wherein I'have illustrated a preferred embodiment of the inven tion;

Fig. 1 is a diagrammatic plan view illustrating 50 the ,general arrangement of the transferer .relay station and its relation to the sending stations;

Fig. 2 is a diagrammatic elevation illustrating parts of the system shown in Fig. I;

Fig. `3 is a plan view showing one desirable arrangement of conveyor belts, driving motors, and 5 chutes at the transfer station;

Fig 4 is a diagrammatic vertical section `on the line 4 4 of Fig. 3; I

Fig. 5 is a diagrammatic side elevation sub; stantially in the plane of line 5--5 of Fig. 3;

Fig. 6 is a diagrammatic front lelevation of the station of Fig. 1;

Fig. '7 is a vertical section illustrating `a set of distributing chutes; Y

Fig. 8 is aside elevation of one desirable form 15 of requisition carrier; and

dFig, 9 is v4a sectionon ,the line 19-9 `of Fig. l'l'.

Referring to the drawings, and particularly to Fig. 2A, A represents a building devoted in vWhole or in part to the business served by the apparatus 29 of the present invention, such building being of any desired height and having floors t and lusual partitions dividing the enclosed space linto ofce or other rooms Which may be grouped in any way to house distinct departmental activities of 25 the business, and in any of which offices or rooms maybe located sending stations S of the carrier dispatch system. The several stations communi cate-,by `Vmeans of suitable conveyors, for example pneumatic tubes, with a transfer station T, con.- veniently located in the basement of the building.

'Ihe transfer station selected for illustration, ,as shown diagrammatically in Fig. l and in plan in Figi-3, comprises endless conveyor belts I I, I 2, I3, I4, I5, I6, Il and I8, the variousconveyors preferably vbeing arranged for transporting carriers through a path Whichrfollows a `course similar'to the -letter .U. ASubstantially rvertical guides ,or side boards 2,0 are disposed along the outer Vmarginal edges of the various conveyors. At the base ofthe -U are assorting stations 2|, 22, 23, 2,4, 2 5 y,aiyldrg `and 'along the ,inner sides of the `U adjacent the conveyors It and I8 are dispatching stations 21, 28, 129, v3|, Y32, -and ,353, While delivery terminals 34,",35, 36 andv31 aredisposed alongoconveyors I-I and lf3 respectively at the outer sides of the U. 'Ihe arrangement of theconveyors in a U-shaped system vis economical of space, and as the various lasserting ,and dispatching stations `are ondthe inner sides of the U, it isassured that 50 an operator may move readily from one station to another, thus facilitating handling of the work and making it possible for one operator to take care of more than one station should this be desirable.

The various conveyorsoperate in the direction indicated by the arrows. Conveyors II and I3 at the outer sides of the U serve to transport carriers from the receiving stations 34, 35, 36

1'() and 31 to the conveyors I2 and I4, respectively,

the latter serving to deliver carriers into an inclined chute 38 which terminates at its lower end between assorting stations 23 and 24. An operator positioned at one or both of these stal5 tions may pick up carriers as they are delivered by the chute 38 and sort them for their destination. At busy times, however, operators at these stations might be unable to handle this work, and for expediting the work during periods of intensive service the auxiliary chutes 39 and 4I, similar to chute 38, are arranged to deliver some of the carriers from conveyors I2 and I4 respectively to operators positioned at stations 2 I, 22 and 25 and 26, respectively.

25 In order that the incoming carriers may be distributed approximately equally between the various assorting stations 2| to 26, the traveling surface of each of the conveyors II, I2, I3 and I4 is divided longitudinally by centrally disposed vertical partitions 42, 43, 44 and 46 respectively.

It will thus be seen that the partition 42 divides the conveyor II into lanes IIa and IIb which communicate with lanes I2a and I2b formed by the partition 43. These lanes all lead directly to the centrally disposed chute 38. At the mouth or receiving end of chute 4I a deflector, such as the vane 4l, is mounted to pivot so that it may be swung diagonally across lane I 2b to direct incoming carriers into the chute 4 I. This deflector may also be swung to position parallel to the conveyor and at the side thereof to allow all carriers to be delivered directly into the middle chute 38 should this be desired. Similarly a vane 48 is mounted at the receiving end of chute 39V therefore, that carriers issuing from delivery terminals 34 will pass through lanes IIa and I 21 to the middle chute and likewise carriers from delivery terminals 36 will pass through lanes Il)a and I4a to the same chute. On the other hand,

carriers issuing from delivery terminals 35 and 31 will be conducted through lanes IIb, I2b and |3b, |4b, respectively, and these carriers may be 80 `allowed to pass directly to the chute 38 or may be diverted through the auxiliary chutes should this be desirable. In this way a very flexible arrangement is provided for taking care of in- 4 coming carriers. Normally, only one operator need be stationed at each of the assorting stations 2| t0 26 and under some conditions, as when business is light, one operator may tend to more than one station, or some of the stations may be closed. However, it will be understood that the number of operators at any or all of the stations may be increased whenever this is considered advisable.

In front of each operators position at assort- M ing stations 2| to 26 a number of openings are -formed in the table top and these openings are connected by means of slides or chutes with a corresponding number of lanes on the conveyors I5, I6, I'I and I8. For the purposes of illustration, each of these conveyors has been divided into three lanes, although it will be understood g that the number of lanes may be varied to suit conditions. Longitudinally extending vertical partitions 52, 53, 54, 55 divide conveyors I5 and I6 respectively into lanes I5a, I5b, I5c and I6, I6b and I6". Similarly partitions 56, 5'I, 58 and 10 59 divide conveyors II and I8 respectively into communicating lanes Ila, I'Ib, I'Ic and |821, |81), Isc. djacent to the dispatch stations 21, 2s, 29 and 3|, 32, 33 deflectors 6I, 62 and 63 cooperate with the partitions 54, 55, 58, 59 and with 15 the guide boards 20 to assist in directing carriers from the various lanes to the proper group of dispatch stations.

At the asserting stations 2| to 26 (Fig. 3), openings 50a, 5l)b and 5Ilz communicate respec- 20 tively with lanes |5'1, I5b and |56, while openings 60e, Ib and 6|)c communicate respectively with lanes I'Ia, I'Ib and IIC. An operator at any one of the stations 2| to 26 may send a carrier to any dispatch station in the groups 2'I to 29 25 and 3| to 33 by depositing the carrier in the opening communicating with the lane which leads to the group in which the desired station is included. Pneumatic tubes 64 lead from these dispatch stations to the stations S 30 (Fig. l) located in the various offices or at other desired points, and return tubes lead from the stations S to the delivery terminals 34, 35, 36, 3l, etc. at the transfer station.

To further expedite the service, certain busy lines, such for example as those leading to the mailing and filing departments, may terminate directly at the sorters section in front of assorting stations 2| to 26. These lines are indicated generally at 68 in Fig. 2 and are provided with 40 suitable receiving and dispatch terminals. These lines are preferably arranged in groups comprising receiving and sending units 69 and 'II respectively which terminate at the sides of the chutes 38, 39 and 4I, as indicated in Figs. l, 4, 5 and 6. 45 Furthermore, certain lines may lead directly from one department to another, as indicated by the lines 12, I3 (Fig. 2) which lead directly from stations 14, I5 to stations 'I'I and 18.

It will be seen from Fig. 6 that the conveyors 50 I2 and I4 which lead directly to the chutes 38, 39 and 4| are disposed above conveyors I5 and I'I which conduct carriers away from the assorting stations 2| to 26. This is a compact, eicieni arrangement which is economical of space and 55 makes it possible to discharge carriers from conveyors I2 and I4 to the asserting table and thence to conveyors I5 and I`I by gravity. Conveyors II and I3 (Figs. 4 and 5) disposed along the outer sides of the U, follow substantially hori- 50 zontal paths from end rollers 9| (Figs. 3 and 4) to intermediate rollers 92 about which the upper course of the belt turns backwardly and around idler rollers 93 and then forwardly in an upwardly inclined direction to end rollers 94 disposed at the mouths or receiving ends of chutes 96. These chutes have partitions 42', 44' (Fig. 6) corresponding to partitions 42, 44, and are arranged to discharge carriers in the proper lanes on con- 70 veyors I2 and I 4, From the end rollers 94 the belts of conveyors and I3 pass downwardly and backwardly around suitable idler rollers 9'I, 9B to the end rollers 9|. A v

Conveyors I2 and I4 operate over end rollers 754V |0I, |02, (Fig. 6) and conduct carriers received from chutes 96 up an inclined path to a substan tially horizontal course Which leads past the auX- iliary chute 39 (or 4|) to the central chute 38. Conveyors I5 and II operate respectively over end rollers |03, |04 and |06, |01 and serve to discharge carriers through chutes |0811, |0811, |080, and |09a, |0911, |69c (Figs. 4 and 5) respectively onto the proper lanes of conveyors I6 and I8. Directly beneath these chutes the conveyors I6, I8 operate in upwardly inclined paths to transport carriers deposited thereon upwardly and then in a substantially horizontal direction to the groups of dispatching stations 21 to 29, 3| to 33. The end rollers for conveyors 6, I8 are indicated at III, I2 and suitable intermediate and idler rollers at I I3, I4. The various conveyors II, I8 may be operated by individual motors |46 or in any other approved manner. A group of slides through which carriers pass from openings 50a, 50h, 50C,

60a, 60h, 60C, (Fig. 3) at the assorting stations t0 the conveyors I5 and I'I are shown in Figs. 4, 7 and 9. From these views it will be seen that the slide H6 (Fig. 7) which serves an opening 50a is substantially vertical, while the remaining slides I II to I2 I are inclined at the proper angles to conduct carriers from the remaining openings to the proper lane. Thus slide is adapted to conduct carriers from an opening 50b to the lane I5b, slide II8 connects an opening 50C with the line |50; while slides IIS, |20 and I2I afford communication respectively between openings 60a, 601, 60 and the lanes I'a, I'Ib, and I'Ic. These slides are preferably in the form of chutes having a rectangular cross section with outwardly directed top flanges f as shown in Fig. 9 and these chutes terminate directly at the partitions which divide the conveying surface into the various lanes. As shown particularly in Fig. 7, the partitions are preferably in the form of spaced plates |22, |23 having overlapping flanges at the bottom and connected at the top to the Vdepending flanges of angles I 26 spaced back-toback and separated by the spacing strip |26, the angles |24 being supported from an upper transverse support such as the angle |21 which in turn is supported from the side boards or guides. As shown in Fig. 7 these side boards may be formed of plates |28 having stiffening angles |29 attached along their upper and lower edges and, of course, it will be understood that suitable framework is provided, as indicated generally at |36 in Figs. 4, 5 and 6, for supporting the guideboards and partitions. It will also be understood that the arrangement of partitions and the guide boards, as shown in Fig. 7 for the conveyors I5 and maybe substantially the same as that used on other conveyors `and. for this reason further illustration of this feature is deemed unnecessary.

As previously pointed out this system of carrier distribution is particularly useful in handling carriers which are not opened previous to reaching their destination. The carriers may be marked with a color scheme to indicate the group of stations '.il-ZQ or .3 |-33 to which they are to be sent. The carriers may also carry numbers or other indicia to designate the particular tube at these stations through which they are to be dispatched.

The carriers are first delivered to the primary sorters table I3I (Fig. 1) where they are sorted by operators according to their color scheme and dispatchedinto the proper lanes which may Valso be indicated with corresponding colors. -On reaching a secondary :sorters table |32 .or I 33 the carriers .are then redispatched by numberthrongh the proper tube. If color group designation is ,not employed, the dispatch tubes may be grouped by numbers and carriers having numbers Within any such group will be delivered to the proper dispatch operator through the appropriate lane by the operator at the sorters table |3| Obviously, any other suitable system of designation may be used. This arrangement leaves the sorting to be done by one or two operators at the chute 38 alone, or when business warrants with additional operators located at chutes 39 and 4| thereby providing great flexibility in the number of operators according to the volume of the business to be handled.

As this system provides service to such a large number of stations, a rover system of carrier distribution has been devised whereby a certain number of carriers are assigned proportionately to each sub-station. A stock of additional carriers is kept at the main transfer station. Carriers arriving at each sub-station are retained there after their contents are removed until the supply becomes excessive, and then these empty carriers are sent back to the transfer station to be put into the reservoir supply. If the supply at the sub-station becomes depleted it is necessary to requisition additional carriers from the main supply. For this purpose a single carrier |35 (Fig. 8) is provided to serve as a requisition for additional carriers. The carrier |35 follows a standard carrier in form and size and diifers only in that the open end is closed with a suitable plug |36 to prevent its use for dispatching papers, and a distinctive color band |37 is painted around the Shell on which is marked the sub-station number (as) to which this carrier belongs. When one of these carriers is received at a transfer station it is passed along to the operator in charge of carrier supply and a suitable number of empty carriers are then sent to the station indicated on the requisition carrier with the signal carrier following the requisitioned carriers.

While apparatus of preferred form has here been shown as illustrative of the invention, it is to be understood that the invention is not necessarily limited to this particular embodiment but that changes in shape, size, number, and relative arrangement of parts as well as the substitution of equivalents fall within the scope of the invention.

I claim:

l. A carrier dispatch system of the kind having a plurality of sending stations and carriers which travel unopened from. one such station to another, and a relay station interposed in the path of carriers moving from one sending station to another, said relay station comprising means adapted to receive carriers from any of said sending stations, Van assorting station, a pluraiity of -redispatch stations each having dispatch terminals, each said terminal communicating with one of the sending stations, and means for causing carriers to move from the assorting station to any selected `dispatch station.

2. A carrier dispatch system of the kind having a plurality of sending stations and carriers which travel unopened from one such station to another, and a relay station comprising means adapted to receive carriers from any of said sending stations and to deliver a part o-f said carriers to one assorting station and a part of said carriers to another assorting station, -a plurality of redispatch stations each having dispatch .terminals, each such terminal communicating with a Asending station, `and .means for moving vcarriers from any one of the asserting stations to any selected redispatch station.

3. A carrier dispatch system of the kind hav ing a plurality of sending stations and carriers which travel unopened from one such station to another, and a relay station comprising means adapted te receive carriers from any of said sending stations and to deliver all of said carriers to a single asserting station or alternatively to deliver a part of said carriers to one asserting station and a part to another asserting station, a plurality of redispatch stations, and means common to the several asserting stations for conveying carriers from the latter te any selected redispatch station.

4. An intercemmunicating carrier dispatch system ofthe kind having a plurality of sending stations and carriers which travel unopened from one of said stations to another, a relay sta- :tion comprising an asserting station at Which the carriers are manually sorted and a plurality of redispatch stations, means for delivering all carriers arriving at the relay station from the several sending` stations to the asserting station,

'i and independent conveyors leading from the asserting station te the several redispatch stations.

5. An intercommunicating carrier vdispatch system of the kind having a plurality of sending stations and carriers which travel unopened from one of such stations te another, a relay station comprising an asserting station and a plurality of redispatch stations, means for delivering all carriers arriving at the relay station from the several sending stations to the asserting station,

conveyor means for transferring carriers from the vicinity of the asserting station to the several dispatch stations, and means for delivering carriers from the asserting station to any selected conveyor means.

6. An inter-communicating carrier dispatch system of the kind having a plurality of sending stations and carriers which travel unopened from one of such stations to another, a relay station comprising a plurality of asserting stations, a plurality of redispatch stations, means operative to deliver all carriers arriving at the relay station from the several sending stations te one of the asserting stations er alternatively to deliver a `part of the arriving carriers to one asserting station and a part to another asserting station, a plurality of independent conveyors leading to the respective redispatch stations, and means for delivering carriers from any of the asserting sta- -tions te any of said independent conveyors.

'7. An intercommunicating carrier dispatch system of the kind having a plurality of sending stations and carriers which travel unopened from one of such stations to another, a relay station comprising a plurality of asserting stations, a plurality of redispatch stations, means operative to deliver all carriers arriving at the relay station from the several sending stations to one of the asserting stations or alternatively to deliver a part of the arriving carriers te one asserting station and a part to another asserting station, conveyors for moving carriers from the several asserting stations to each of the redispatch statiens, and independent chutes leading from each asserting station to each of said conveyors.

8. An intercommunicating carrier dispatch system of the kind having a plurality of sending stations and carriers which travel unopened from one of such stations to another, a relay station comprising an asserting table, a delivery chute leading thereto, a plurality of redispatch stations, conveyor means adapted to receive carriers from the several sending stations and to deposit them in the delivery chute, and conveyor means for receiving carriers from the asserting table and transferring them to any selected redispatch station.

9. An intercommunicating carrier dispatch system of the kind having a plurality of sending stations and carriers which travel unopened from one of such stations to another, a relay station comprising an asserting table, a delivery chute leading thereto, a plurality of receiving conveyors to which carriers are delivered from certain groups respectively of sending stations, said conveyors being adapted to deliver all such carriers to the asserting table, a plurality of redispatch stations having dispatch terminals corresponding respectively to certain groups of sending stations, and means for transferring carriers from the asserting table to any selected redispatch station.

l0. An intercommunicating carrier dispatch system of the kind having a plurality of sending stations and carriers which travel unopened from one of such stations to another, and a relay station comprising spaced parallel conveyor belts, a plurality of delivery terminals arranged to deliver carriers from certain of said sending stations to each of said belts, an asserting station, a chute at said station arranged te permit an operator to work at either side thereof, means for transferring carriers from each of said conveyor belts to said asserting station, redispatch terminals arranged in a plurality of separate banks, and means within convenient reach of each eperator at the asserting table for receiving carriers for delivery to any of said banks of redispatch terminals.

ll. Ari intercommunicating carrier dispatch system of the kind having a plurality of sending stations and carriers which are dispatched from one of said stations to another, and a relay station comprising spaced parallel conveyor belts, a plurality of delivery terminals arranged to deliver carriers from certain of said sending stations to each of said belts, transfer belts transverse to said conveyor belts adapted to receive carriers from the latter, and a plurality of asserting chutes, said transfer belts being adapted to deliver all carriers te one of said chutes, and adjustable means associated with said transfer belts for optionally diverting carriers carried by each transfer belt to another chute.

l2. An intercommunicating carrier dispatch system of the kind having a plurality of sending stations and carriers which are dispatched from one of said stations to another, and a relay station comprising spaced parallel conveyor belts, a plurality of delivery terminals arranged to deliver carriers from certain of said sending stations to each of said belts, a plurality of banks of redispatch terminals arranged substantially parallel to each conveyor belt, a row of asserting 6 stations interposed between said belts, chutessubstantially parallel te the belts for delivering carriers te the respective asserting stations, transfer means for delivering carriers from the belts to the chutes, a plurality of parallel conveyors comprising portions extending along the row of asserting stations, said conveyors corresponding to the several banks of redispatch terminals, and chutes at each asserting station for delivering carriers to any selected oneof the parallel conveyors;v

13, An intercommunicating dispatch system of the kind having a plurality'of sending stations and carriers which travel unopened from one of such stations to another, a relay station interposed between a pair of such sending stations, said relay station comprising a plurality of chutes each arranged to permit an assorting operator to be stationed at each side thereof, means for delivering all arriving carriers to one of said chutes or alternatively to deliver a part of said carriers to one chute and a part to another, redispatch terminals disposed in banks remote from said chutes, and conveyor means accessible to any assorting operator stationed at any of the respective chutes for transferring carriers to any selected bank of redispatch terminals.

14. An intercommunicating carrier dispatch system of the kind having a plurality of sending stations and carriers which travel unopened from one of such stations to another, and a relay station substantially U-shaped inY plan interposed between a pair of such sending stations, said station having receiving and dispatch terminals arranged along the parallel legs of the U and an assorting station at the closed end of the U, and means for transferring carriers from the reiving terminals to the assorting station and from the assorting station to the redispatch terminals.

15. An intercommunicating carrier dispatch system of the kind having a plurality of sending stations and carriers which are dispatched from one of said stations toanother, and a relay station comprising substantially parallel conveyor devices, and delivery terminals associated with each such conveyor device for delivering carriers from sending stations thereto, an assorting station disposed between said conveyor devices, means for transferring carriers from the respective conveyor devices to the assorting station, a plurality of banks o f redispatch terminals, said banks being disposed substantially parallel to said conveyor device, and means for transferring carriers from the assorting station to the several banks of redispatch terminals.

16. An intercommunicating carrier dispatch system of thekind having a plurality of sending stations and carriers which are dispatched from one of said stations to another, and a relay station comprising a plurality of conveyors, two rows of delivery terminals for delivering carriers fom sending stations to each conveyor, means providing separate paths for the carriers delivered from the respective rows of terminals as they are moved along by the conveyors, a plurality of assorting chutes, deflector means adjustable to cause all carriers on the conveyors to enter one of said chutes or alternatively to cause carriers moving in one carrier path to enter one chute and carriers in another carrier path to enter another chute, redispatch terminals, and means for transferring carriers assorted at said chutes to the redispatch terminals.

17. An intercommunicating carrier dispatch system of the kind serving a plurality of distinct departments each including a plurality of sending stations and carriers having primary index characteristics corresponding to departments and secondary index characteristics corresponding to individual sending stations, said carriers being designed for dispatch from any station to any other station of the system, and a relay station through which carriers on their way from one sending station to another must pass, said relay station comprising a primary assorting station at which carriers are manually assorted in accordance with their primary index character- Y -istics, and a secondary assorting and redispatch station, corresponding to each of the several departments, where carriers are assorted in accordance with their secondary characteristics and foWarded to the corresponding sending stations, and independent means for transferring carriers 10 having diierent primary characteristics from the primary assorting station to the several redispatching stations.

18. `An intercommunicating carrier dispatch system of the kind serving a plurality of send-'15 ing stations and having carriers designed to be sent from any station of the system to any other station, a reserve station through which all carriers pass on their way from one sending station to another, and a requisition carrier for each 20 sending station having characteristics identifying its station, said requisition carrier being so constructed as to preclude its use for general purposes but beingadapted for dispatch from its sending station to the reserve station to notify 25 an operator at the latter station whenever the supply of carriers at said sending station requires replenishment.

19. An intercommunicating carrier dispatch system of pneumatic type designed to serve a plurality of sending stations and having carriers adapted to receive material to be sent from any station to any other station of the system, a

. reserve station through which all carriers pass on their way from one sending station to another, and a requisition carrier for each sending station, said requisition carriers being similar to the other carriers but being permanently closed to prevent their use as regular carriers and having index characteristics identifying their respective sending stations, said requisition carriers, when delivered at the reserve station, giving notice to the operator at such station of the depletion of the supply of usual carriers at the station from which the requisition carrier was sent.

20. A carrier dispatch system of the kind having a plurality of sending stations and carriers which travel unopened from one such station to another, and a relay station interposed in the path of travel of carriers moving from one such station to another, said relay station comprising means for receiving carriers and for redispatching carriers.

21. A carrier dispatch system of the kind having a plurality of sending stations and carriers which travel unopened from one such station to another, and a relay station interposed in the path of travel of carriers moving from one such station to another, said relay station comprising carrier receiving means, an assorting station, and redispatch means.

22. A method of dispatching carriers at a central station in a pneumatic carrier system which comprises segregating a plurality of carriers at a distributing point into groups coordinated 6 with their ultimate destinations according to eX- ternal appearance, transmitting each group of carriers to a separate dispatching station, and inserting the carriers at each station in the appropriate tube corresponding to the ultimate destination.

23.*A method of dispatching carriers from one point to any one of a plurality of other points in a pneumatic dispatch system which comprises 15 numbering the destination points and dividing them into groups, selecting at the sending point a carrier of characteristic appearance corre sponding to the groups of the desired destina- 5 tions, designating on the carriers the particular destinations within the groups, delivering the carriers to a distributing station for sorting into the groups, transmitting each group to a separate dispatch station, and dispatching the carriers at each such station to the ultimate destinations designated on the carriers.

FRANK W. MACMARTIN. 

